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Building an extension, garage conversion or conservatory?

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Extensions
Conservatories
Garage conversions

Building an extension?

This is a complex building project so you should seek professional advice from an architect or building contractor before starting.

Watch our video: Do I need building regulations for my extension?

Do I need building regulations for my extension?

An extension will have a major effect on your home, garden and neighbours.

In drawing up plans you will need to look at how it would affect things like access to your home and garden, movement in and around your home and the natural light in existing rooms. You will also need to consider what building materials to use – particularly if your home was built using unusual construction techniques or materials.

Once you have decided your home is suitable for an extension you should get plans drawn up by an architect or building designer and get them approved by your local council’s building control team before starting work.

Plans & details should cover:

  • Foundations – ground conditions, depth, damp proofing and radon protection
  • Floors and walls – structure and strengthening, insulation and sound proofing
  • Roofs – flat or pitched, insulation, supports and beams, headroom
  • Drainage – connections to existing drains, manholes and water supply Electrics, power and heating Windows, doors and ventilation and disabled accessibility
  • Fire safety – escape routes and smoke detectors. In addition if an extension is planned to be two or more storeys, the plans will also need to cover
  • Stairs, handrails and bannisters
  • Sound-proofing – particularly in any sleeping accommodation
  • Fire escape – from upper floors

Watch our video: A building control case study of building an extension

Do I need Planning Permission for my extension?

Find out on the Planning Portal website.

Building a conservatory?

Many conservatories, summer houses, sheds and outbuildings can be constructed without building regulation approval. The general rule is that if they are small (less than 30m2), or are built of non-combustible material, or are separated from nearby buildings or land and do not contain sleeping accommodation they are exempt from the requirement to submit an application – although it is best to check with your local building control team before starting work.

Conservatories generally have to be constructed of mainly translucent walls and roofs and have an external type door separating them from the rest of the house.

Foundations and floors can be constructed in a variety of ways, but need to take account of ground conditions, trees and existing drains. It is also good practice to include insulation to make the conservatory easier to heat.

Conservatories constructed of uPVC should have frames that carry British Standard marks (BSEN 126908 and/or BS7412) to make sure they are strong enough to support the weight of the roof. Wooden conservatories will generally require treatment such as staining or oiling to maintain their reliability. You should check the timber comes from sustainable sources. Glazing should be toughened or safety glass. 

Watch our video: Conservatories basic rules

Garage conversions

Like home extensions, converting garages into a living space is a complex building project and you should seek professional advice from an architect or building contractor and check with your local council building control team before starting. Particular attention will need to be paid to the following when drawing up plans:

  • Foundations – often the foundations of a garage are not deep enough to handle the extra weight of floors, walls and ceilings so will need to be tested to see what strengthening is needed. Infilling door opening – should include suitable foundations, damp course, weather proofing and insulation.
  • Structural strength – often garage walls are of single layer of bricks which may not be suitable to carry an additional floor, new roof or additional insulation.
  • Weather proofing and insulation – the garage will need to be weather proofed and insulated if it is to be used as a living space.
  • Windows and ventilation – windows will need to meet minimum energy efficiency standards and have adequate ventilation provided Watch our video on garage conversion to find out more.

Watch our video: Garage conversions